| 摘要 |
PURPOSE: To prevent sudden supplying of toner accompanying the fluctuation in a toner patch density by releasing the control of a toner suppling amount based on the result of measuring a toner patch density when abnormality occurs in a latent image condition control based on the potential of a photoreceptor. CONSTITUTION: An arithmetic unit 41 controls the charging condition and/or exposure condition of a photoreceptor 42 as a latent image condition based on the result of measuring the potential of the photoreceptor 42 by a potentiometer 48. A patch generator 26 generates patch data so as to create a toner patch for exposure condition setup and toner density control in a specified area other than an image region on the photoreceptor 42 and a selector 27 supplies either this patch data or analog image data to a comparator 24. Then, the arithmetic unit 41 controls a toner supplying amount based on the result of measuring a toner patch density by a densitometer 49 and when detecting abnormality in the latent image control based on the measuring result of the potentiometer 48, it releases its control of the toner supplying amount. |
